Demonic by Stefanie Dawn

You think your soul is simply something you sacrifice after you die? Something you don’t have to think about between now and the moment you leave this mortal realm?
No.
You’ll devote your life to me. You’ll worship me. In turn, I’ll worship you and your body however I desire. From now until the darkness of eternity swallows us both whole in this realm and the next.
You’ll be mine.

I summoned a demon. How was I supposed to know it would actually work?

Now for the revenge I sought, he demanded my soul and my body…

And I would give it to him.